Interpretive Summary: In this opinion article, we develop the hypothesis that the host range for a group of plant and animal infecting viruses called 'rhabdoviruses' is determined mainly by the insect that transmit these viruses. Barriers to virus transmission by the insects are identified and discussed, as are potential avenues for future research. This article reviews recent research on rhabdoviruses and develops new hypotheses about virus transmission by insect vectors. Because of the review, it will appear in a journal read by a large number of diverse scientists. The new ideas put forth should have a large impact on the scientific community.

Technical Abstract:
Rhabdoviruses affect human health, terrestrial and aquatic livestock, and crops. Most rhabdoviruses are transmitted by insects to their vertebrate or plant hosts. For transmission to occur, rhabdoviruses must negotiate insect barriers to acquisition, replication, movement, escape and inoculation. A better understanding of teh molecular interactions of rhabdoviruses with insects will clarify the complexities of rhabdovirus infection processes and epidomiology. A unique opportunity for studying how insects become hosts and vectors of rhabdoviruses is provided by five maize-infecting rhabdoviruses that are differentially transmitted by one or more related species of two divergent homopteran families.